Darwin's Doubt: The Explosive Origin of Animal Life and the Case for Intelligent Design

by Stephen C. Meyer

Neo-Darwinism seeks to explain the origin of novel body plans by starting with simpler body plans and gradually assembling animals with more complex body plans via the gradual accumulation of small successive material variations. Thus, neo-Darwinism employs a “bottom-up” mode of causation. With a bottom-up approach, small-scale diversification should eventually produce large-scale morphological disparity—differences in body plan. The “bottom-up” metaphor thus describes a kind of self-assembly in which the gradual production of the material parts eventually generates the organization of the whole. This suggests in turn that the parts stand causally prior to the organization of the whole. As I have argued, however, this approach encounters both paleontological and biological difficulties: the fossil record leaves no evidence of such a process and the morphological innovation and transformations that it requires are, in any case, biologically implausible.